Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
  • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B30—PRESSES
  • B30B—PRESSES IN GENERAL
  • B30B5/00—Presses characterised by the use of pressing means other than those mentioned in the preceding groups
  • B30B5/04—Presses characterised by the use of pressing means other than those mentioned in the preceding groups wherein the pressing means is in the form of an endless band
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B44—DECORATIVE ARTS
  • B44B—MACHINES, APPARATUS OR TOOLS FOR ARTISTIC WORK, e.g. FOR SCULPTURING, GUILLOCHING, CARVING, BRANDING, INLAYING
  • B44B5/00—Machines or apparatus for embossing decorations or marks, e.g. embossing coins
  • B44B5/02—Dies; Accessories

Definitions

• the present invention relates to a method of galvanic structuring of endless pressing bands.
• Pressing bands are used for continuous manufacture of laminated products and for coating of wood chip boards.
• the surface structure of the pressing bands is transferred in a pressing step under the action of pressure and temperature to the laminated product or to the coated wood chip board. Fine grain structures, wood pore representation and other geometrical designs are used as impression structures.
• the structure supporting surface is in all cases the outer surface of the pressing band which is additionally coated with a wear resistant hard chromium layer to maintain the load during the pressure application in so-called multi-layer presses. Frequently in the pressing bands also the inner side is provided with such a hard chromium layer.
• an upper band and a lower band are utilized. They run synchronously with one another, and the coated chip board or the respective press laminate is treated between the associated runs of both pressing bands.
• Such endless pressing bands are usually produced from steel band material with a thickness of 1-2 mm. Both ends of the steel band are connected with one another by means of conventional welding processes, for example laser or plasma welding. After the formation of the welding seam the welding seam zone must be treated. The treatment is performed by grinding the welding beads with simultaneous removal of fusing residues in the heating zone or the material bead region. After the preparation works in the welding seam zone the endless row bands are finely ground over the whole outer and inner surfaces, and thereby each band obtains its own material thickness with high tolerance accuracy. In some cases, further surface treatments are provided, for example mirror finishing.
• the steel for the steel band material mainly austenitic and martensitic steels are used with predetermined alloying ingredients.
• the alloying ingredients include the following average values: carbon 0.1%, silicium 0.6%, manganese 1.4%, chromium 17.5%, nickel 7.5%.
• the material values include a pulling strength of approximately 1,200 N/mm 2 , a yield point of 980 N/mm 2 , an elasticity limit of 600 N/mm 2 and an elongation of 22%.
• the alloying ingredients include the following average values: carbon 0.05%, silicium 1%, manganese 1%, chromium 13%, nickel 4%, and titanium 0.3%.
• the material values include a pulling strength of 1,080 N/mm 2 a yield point of 1,000 N/mm 2 , an elasticity limit of 850 N/mm 2 and an elongation of 5%.
• Sample pressing bands of martensitic and austenitic alloys with one or several welding seams within an endless band were provided for experiments first with an etching-resistant printing ink in form of a design pattern having selectively a grain design or wood pore design.
• the sample band was suspended in a conventional acid immersion bath, and therefore as known a metal removing takes place on the metal-blank points which are free from the printing ink. Thereby the later printing image is produced.
• This metal removing process positively exposes the welding seam zones.
• a non-uniform structural image is recognized on all pressing bands in the welding seam zone. Undesired bead-like elevations in the welding seam zones are visible, each possibly can be traced back to the fact that in the direct welding seam zone a lower etching speed in the acid bath takes place than in the remaining welding seam-free regions.
• a galvanic structuring of endless pressing bands is performed with the use of a steel band which is treated in an acid bath and has a welding seam.
• the steel band has the following alloying ingredients:
• a specific alloy in accordance with the present invention can have the following composition:
• an acid bath has the following composition:
• the phosphorus portion is for example 45%, while the sulfuric acid portion is 34%.
• the acid bath is subjected to the action of a direct current with a current density 3 ampere/dm 2 .
• the inner side, the outer side, or both sides of the band are galvanically treated. It is especially advantageous when the pressing bands for structuring are subjected to the acid action in the immersion bath during 30-60 minutes. In this case a structuring depth of 30-60 thousandth millimeters is obtained.
• a pressing band of a desired length is first taken from a steel band coil with an alloying composition in accordance with the present invention, and the welding butt points are cut straight or inclinedly.
• the steel band coil in many cases are ground at both sides, or in other words is free of fuse or corrosion defects.
• Different methods can be used for welding. Frequently, a known process is used under the name WIG process.
• WIG process a known process is used under the name WIG process.
• After this the welding seam and the whole outer and inner surfaces of the pressing band are ground to a uniform material thickness.
• the finely ground outer surface is then finely polished to a roughness equal to or smaller than 1 mu.
• the outer side of the band is imprinted with the desired design pattern which uniformly covers the whole outer surface and the printing pattern forms a seamless transition at the printing start and printing end.
• the thusly prepared pressing band is suspended in an acid inversion bath in which the metal-blank locations between the pressing patterns are dissolved.
• the action of the acid is dependent on the desired structuring depth.
• Eventual ridge formations in the etched structure are removed with a polishing roller, and then the pressing band is withdrawn from the immersion bath.
• the structured band is provided with a hard chromium layer in another immersion bath. This layer can be applied for example by sand blasting with a uniform gloss value.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Electroplating Methods And Accessories (AREA)
• Heat Treatment Of Sheet Steel (AREA)
• Pressure Welding/Diffusion-Bonding (AREA)

Applications Claiming Priority (2)

Publications (1)

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Citations (7)

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• 1991
  • 1991-10-23 DE DE4134976A patent/DE4134976C2/de not_active Expired - Fee Related
• 1992
  • 1992-09-29 SE SE9202803A patent/SE9202803L/ not_active Application Discontinuation
  • 1992-09-30 US US07/954,919 patent/US5350465A/en not_active Expired - Fee Related
  • 1992-10-01 IT ITMI922284A patent/IT1255712B/it active IP Right Grant
  • 1992-10-16 CH CH322492A patent/CH686502A5/de not_active IP Right Cessation
  • 1992-10-22 AT AT0209492A patent/AT403022B/de not_active IP Right Cessation
  • 1992-10-23 JP JP4286280A patent/JPH05331700A/ja active Pending

Patent Citations (7)

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